Compressor-regulating apparatus



Jan: 14, 1930. E. L. BUCKLEY ET AL COMPRESSOR REGULATING APPARATUSINVENTORS .E'mozagLBuqjrleZ j m on c 211810- 7H1]? ATTORNEY.

File March 19, 1928 .0 Fr; a

Patented Jan. 14, 1930 UNITED STATES inner-e SPATENT @FFEQE'.

EMORY L. BUCKLEY AND RAYMOND C. MCALLISTEB, OF PAINTED EOST, NE'W YORK,

ASSIGNORS TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A COR-PORATION OF NEXV JERSEY GOMPRESSOR-REGULATING- APPARATUS Applicationfiled March 19, 1928.

by the operation of the valve.

Other objects and advantages of the invention will be in part obviousand in part pointed out hereinafter.

The drawing shows a vertical section through a regulator and pilot valveconstructed in accordance with the practice of the invention. Thecylinder and its inlet valves associated with the pilot valve also areshown in horizontal section and on a reduced scale with respect to thepilot valve.

Referring to the drawing, the invention is shown associated with acompressor comprising a cylinder A having a piston B and clearancecontrolling valves C, D, E and F associated with suitable clearancepockets G, H,

J and K respectively. The clearance valves 0, D, E and F are adapted tobe operated or kept closed by the pressure of motive fluid in suit-ablechambers L provided with pistons O which press the valves C, D, E and Fto their seats. If pressure is relieved in the chambers L, suitablesprings P return the pistons O lifting the valves C, D, E and F fromtheir seats thereby increasing the clearance of the cylinder A andunloading the compressor a predetermined amount. The compressor cylinderA is unloaded in steps depending upon the air consumption of theapparatus connected with the discharge of the compressor and it istherefore desirable that the clearance valves G, D, E and F should beopened successively. In this arrangement the compressor is thereforeadapted to be operated at full load, three-quarter load, onehalf load,one-quarter load, or no-load, de-

pending upon the position of the valves C, D, E and F as will beunderstood. the drawing, the compressor is indicated as operating atthree-quarter load, the valve 0 being shown open so as to increase theclear- As shown in Serial No. 262,827.

ance of the cylinder by adding the clearance of the chambers G.

The regulating apparatus for operating the valves C, D, E and F includean arm Q pivoted at one end as at R to support S mounted on a suitablebase T, the arm Q being weighted at its end U opposite the pivot R andheld balanced by means of air pressure from the discharge line (notshown) of the compressor. Suchmotive fluid under pressure is admittedthrough a pipe V into a base lV fitting within cup X mounted on the baseT and such pressure is exerted against a second cup Y within anexpandable member Z, such as a sylphon attached to the member VJ. Thesecond cup Y is provided with a pointed rod 6 resting in that cup andbearing against the arm Q on a knife edge 0.

A pilot valve is provided to control the admission and exhaust of motivefluid or compressed as from the cylinders L. his pilot valve includes avalve chamber (Z having a longitudinal bore 0 provided withlongitudinally spaced ports 7', g, h and j associated with the clearancecontrol valves C, D, E, and F respectively by means of suitable pipes70, 0, p and 5 respectively. lVithin the valve chamber bore a, a pistonr is adapted to reciprocate to control the exhaust of motive fluid orcompressed gas from the chambers L. The admission of such motive fluidinto the chambers L is accomplished by the provision of a supply pipe 8connected to a port t in the bore 6, the piston r bein provided with aneck a between its ends so as to permit motive fluid to pass from theport If to one or more of the ports 7", 9, 7L and when the latter portsare not uncovered by the end of the piston 1 The lower end of the pistonr is relatively narrow as shown at '11 so as to prevent motive fluidfrom passing to the lower end of the bore 6 which is provided with anoutlet 10 and an exhaust pipe :0.

The upper end of the piston r is connected by means of a rod y and pivotz to the arm Q, so as to reciprocate as the arm Q raises or lowers.

The operation of the apparatus so far de scribed is as follows :When thepressure in the discharge line of the compressor reaches a predeterminedamount, the arm Qis raisedby that pressure exerted under the secondmentioned cup Y. The arm Q thereupon raises the piston 1' so that itsend Q) uncovers in succession the ports f, g, It and y closing suchports to the admission of motive fluid from the port 25 and permittingthe exhaust of compressed gas from the chambers L associated with theclearance valves C, D, E and F respectively. Usually the completeunloading of the compressor is not desirable or necessary since theconsumption of the motive fluid compressed by the piston B usuallycontinues though not at the full rate. It is therefore desirable thatonly one of the valves G, D, E and F be opened at a time so as togradually unload the compressor to the required degree. The dischargepressure will lift the arm Q sulficiently to uncover the port 7",thereby accomplishing onequarter unloading or three-quarter loading atwhich time the compressor gas is discharged from the port 7 into theexhaust pipe at.

If the compressor is indoors or is compressing an unpleasant or noxiousgas, it is not desirable to permit the gas to discharge near thecompressor and therefore the exhaust pipe as is often long causing aconsiderable back pressure in the bore 6 under the head '0 of the piston1". It will be noted that the arm Q is delicately balanced by thepressure under the cup Y and often therefore the pressure of the exhaustpressure onto the piston 1" causes the piston to rise, sometimes raisingit sufficiently far to uncover one or more of the ports f, 9, IL or y.This effect is cumulative since the additional exhaust pressure from theport 9 will send the piston r further up and uncover the port h and arepetition of this action sends the piston still further up.

This is avoided by the provision of a latch to lock the piston 1" inposition after uncovering one of the ports f, g, h or y. The latchincludes a plunger 2 slidable in a guide 3 and attached at its upper endby a pivot 4 to the arm Q. Below the guide 3 in the base T is provided aroller 5 to further support the plunger 2. The plunger 2 is providedwith notches 6, 7, 8 and 9 corresponding to the positions of the pistonr with respect to the ports f, g, h and j at three-quarter load,one-half load, one-quarter load and no-load respectively. A detent isprovided to cooperate with the notches, 6, 7, 8 and 9 so as to preventslight movements of the arm Q. This detent includes an arm 10 mounted ona pivot 11 and provided at its free end with a rotatable square block 12engaging the notches 6, 7, 8 and 9. The arm 10 is pressed against theplunger 2 by means of a spring 13 held in place in the base T by meansof a screw 14. The detent is adapted to prevent only the slightertendencies of the arm Q to move.

The arm Q is prevented from moving due to exhaust pressure from theports f, g, hand y' under the piston r by means of a second arm 15 whichis normally out of engagement with the notches 6, 7, 8 and 9 being heldin this position by a coil spring 16 at one end. The spring 16 is heldin position by a screw 17 similar to the screw 14. The opposite end ofthe arm 15 is provided with a pin 18 which is adapted to fit into thesquare bottoms of the notches 6, 7, 8 and 9 and when in that position,the plunger 2 is rigidly held against movement. It is desirable thatmovement of the plunger 2 should be prevented only temporarily and onlyafter one of the ports f, g, h and j has been uncovered. To this end thearm 15 is operated by the pressure of the exhaust existing in the pipe00. Such pressure is transmitted to a cylinder 19 provided with a pistonplunger 20 having a piston rod 21 adapted to bear against the arm 15. Apipe 22 connects the cylinder 19 with the exhaust pipe :0. If v desired,the pipe 00 may be smaller as at 23 if it connects with the pipe 22.

It will thus be seen that when the exhaust occurs from one of the portsf, g, h and j into the lower end of the bore 6, pressure is transmittedthrough the pipes a0 and the pipe 22 into the cylinder 19 whereupon thepiston 20 is pushed forwardly and its piston rod 21 presses against thearm 15 to cause the pin 18 to engage one of the notches 6, 7 8 or 9thereby locking the arm Q and the piston r rigidly in position afterhaving uncovered one of the ports f, g, h or 7'. When the exhaustpressure has been dissipated through the pipe 23, the spring 16 returnsthe arm 15 to its normal disengaged position and permits furthermovement of the arm Q and the piston upon corresponding rise ofthe'pressure in the discharge line of the compressor.

Thus by the above construction are accomplished among others the objectshereinbefore referred to.

We claim: 7

1. A compressor regulating apparatus comprising in combination a pilotvalve having a valve chest provided with a plurality of ports and alongitudinally movable piston adapted to control exhaust of air underpressure from said ports to the atmosphere, and pressure actuated meansto prevent such exhaust from eifecting further movement of said piston.

2. A compressor regulating apparatus comprising a pilot valve having avalve chest provided with a bore and spaced ports in said bore, and apiston longitudinally movable in said bore to control the exhaust ofcompressed gas from said ports to atmosphere, and means actuated byexhaust pressure to prevent movement of said pilot valve by such exhaustpressure during its passage through the bore.

3. A compressor regulating apparatus comprising a pilot valve having avalve chest provided with a bore and spaced ports in said bore, a pistonlongitudinaly movable in said bore to control the exhaust of compressedgas from said ports to atmosphere, and a latch actuated such exhaust ofpressure to lock said piston in place after uncovering one of saidports.

-l-. A compressor regulating apparatus comprising a pilot valve having avalve chest provided with a bore and spaced ports in said bore and apiston longitudinally movable in said bore to control the exhaust ofcompressed gas from said ports to atmosphere, and a latch temporarilyactuated by exhaust pressure to lock said piston in place afteruncovering one of said ports.

5. A compressor regulating apparatus comprising a pilot valve having avalve chamber with a bore having spaced ports therein, a pistonlongitudinally movable in said bore to control the exhaust of compressedgas from said ports to atmosphere, a latch adapted to lock said pistonagainst movement after said piston has uncovered one of said ports, anda detent spring actuated to resist movement of said piston.

6. A compressor regulating apparatus comprising a pilot valve having avalve chamber with a bore and ports spaced in said bore and a pistonlongitudinally movable in said bore to control the exhaust of compressedgas from said ports into said bore, a latch operated by the pressure ofsuch exhaust to lock said piston temporarily in position afteruncovering one of said ports, and a spring operated detent normallyresisting movement of said piston.

7. A compressor regulating apparatus comprising a weighted arm pivotallymounted, pressure operated means for moving said arm, a pilot valveoperated by said arm hav ing a valve chest provided with portscommunicating with unloading valves of the compressor, said ports beinglongitudinally spaced from each other, a longitudinally movable pistonin said valve chest to control the exhaust of compressed gas from saidports and operable by said arm, and a latch operable by the pressure ofsuch exhaust to hold said arm and piston rigidly in position after saidpiston has uncovered one of said ports.

8. A compressor regulating apparatus comprising a pivotally mounted arm,means actuated by the discharge pressure of said compressor forbalancing and moving said arm, a pilot valve operable by said arm havinga valve chest provided with ports associated with the unloading valvesof the compressor, a piston longitudinally movable to uncover said portssuccessively upon movement of said arm, aplunger movable by said armprovided with notches corresponding to the ports in said valve chest,and a latch arm to engage the notches of said plunger and temporarilyoperated by the exhaust from said ports when uncovered by the piston tolock said arm and piston in position until said exhaust is dissipated,and a spring actuated detent cooperating with said notches to resistmovement or" said plunger.

9. A compressor regulating apparatus, comprising a pilot valve having avalve chest provided with a bore, ports in the valve chest opening intothe bore at spaced intervals along the length thereof, an atmosphericvent at one end of the bore, a reciprocable piston in the bore tocontrol communication between the ports and the vent, and means actuatedby the exhaust pressure flowing from said atmospheric vent to preventmovement of the piston by such exhaust pressure during its passagethrough the bore.

In testimony whereof we have signed this specification.

EMORY L. BUCKLEY. RAYMOND C. MOALLISTER.

